Parking brake actuation assembly

Abstract

A brake actuation assembly comprising a thrust and support element comprising a first thrust end adapted to cooperate with a first jaw of a brake; the thrust and support element comprising a second thrust and support element end; a lever rotatably supported to the thrust and support element for rotating at least along a rotation thrust direction; the lever comprising a first lever end adapted to cooperate with a second jaw of the brake; the lever comprising a second lever end, wherein the second lever end comprises a hooking seat; and wherein the hooking seat is adapted to firmly receive a connecting portion of a coupling end of a traction cable, the traction cable having a cable body capable of an elastic flexural deformation; the hooking seat being arranged undercut with respect to the rectilinear development direction of the cable body; the lever being adapted to oscillate; wherein the lever comprises a lever abutment surface which cooperates with a stop abutment counter-surface provided in the thrust and support element to prevent a free rotation of the lever in the opposite direction to the rotation thrust direction; the thrust and support element and the second lever end delimiting a guide channel which allows the passage of at least the coupling end; the guide channel allowing the coupling end to rotate about the second lever end and to be coupled to the hooking seat upon the elastic return of the cable body to a substantially straight cable body position, preventing the rotation of the lever in the opposite direction to the rotation thrust direction.

The invention claimed is: 
     
       1. A brake actuation assembly, comprising:
 a thrust and support element comprising a first thrust end of thrust and support element adapted to cooperate with a first jaw of a brake; said thrust and support element comprising a second thrust and support element end; 
 a lever rotatably supported to said thrust and support element for rotating at least along a rotation thrust direction; 
 said lever comprising a first lever end adapted to cooperate with a second jaw of the brake; 
 said lever comprising a second lever end, wherein said second lever end comprises a hooking seat; and 
 wherein said hooking seat is adapted to firmly receive a connecting portion of a coupling end of a traction cable, said traction cable having a cable body capable of an elastic flexural deformation that allows it to return to the straight position when the bending stress is removed; 
 said lever being adapted to rotate only when subjected to the traction action of the traction cable, for acting with the first lever end against said second jaw of brake; 
 wherein 
 said thrust and support element comprises an inner element wall which at least partly delimits a guide channel; and 
 said lever comprises a lever inclined wall which at least partly delimits said guide channel; 
 wherein a safety distance (D) between a first straight line (R 1 ), parallel to a rectilinear extension of the traction cable in a non-bent position, passing by a lever end located at an end of the coupling end of the lever, and a second straight line (R 2 ), parallel to the rectilinear extension of the traction cable in a non-bent position, passing by an inner wall end located at an end of the inner element wall which substantially faces the lever 
 wherein said safety distance (D) is less than a maximum transverse dimension (K) of said coupling end
     D<K    
 
 
       and wherein said inner element wall and a lever inclined wall therebetween define a minimum distance (d), wherein said maximum transverse dimension (K) is equal or less than the minimum distance (d) between said inner element wall and said lever inclined wall;
     K≥d    
 
       and wherein
 said lever comprises a lever abutment surface which cooperates with an abutment counter-surface provided in said thrust and support element to prevent a free rotation of the lever in the opposite direction to said rotation thrust direction; 
 said thrust and support element and said second lever end define said guide channel which allows the passage of at least the coupling end when the cable body is elastically bent, to maintain said lever in a stationary position during both assembly or disassembly of the traction cable; 
 said guide channel allowing the coupling end to rotate about said second lever end and engage with said hooking seat upon the elastic return of the cable body in a cable body position substantially straight, preventing the rotation of the lever in the opposite direction to said rotation thrust direction when the coupling end rotates about said second lever end. 
 
     
     
       2. The assembly of  claim 1 , wherein
 said lever inclined wall forms a slide which guides said connecting portion of the traction cable in said guide channel by bending of said elastic cable body in bending from its rectilinear balance direction to that bent bypassing the second lever end for the coupling, for example in the undercut of the coupling end of the traction cable to said hooking seat of the lever 
 and said hooking seat is arranged undercut with respect to the rectilinear development direction of the cable body. 
 
     
     
       3. The assembly of  claim 1 , wherein
 said lever comprises a plate-shaped lever body; and 
 said coupling end of said connecting portion of the traction cable comprises a cable slot adapted to fit at least a portion of said second lever end coupling said hooking seat in the undercut. 
 
     
     
       4. The assembly of  claim 1 , wherein
 said lever comprises a lever body comprising two arms forming lever prongs which are mutually spaced apart to delimit a central prong seat, each prong comprising a hooking seat for coupling a portion of a coupling end of the traction cable; and 
 said coupling end of the traction cable comprises an enlarged head adapted to couple in the undercut on both coupling seats of the prongs; and 
 said enlarged head comprises a hammer-shaped transverse portion; or 
 said enlarged head comprises a hemispherical or spherical portion. 
 
     
     
       5. The assembly of  claim 4  wherein
 said enlarged head comprises a hammer-shaped transverse portion; or 
 said enlarged head comprises a hemispherical or spherical portion. 
 
     
     
       6. The assembly of  claim 1 , wherein
 said traction cable is a Bowden cable. 
 
     
     
       7. The assembly of  claim 6  wherein
 said bent metal sheet forms two substantially facing walls which delimit a central lever seat which houses the lever; and 
 said bent metal sheet comprises, in the zone of the first thrust end, the two facing walls deformed and brought in contact with each other, defining said inner element wall. 
 
     
     
       8. The assembly of  claim 1 , wherein
 said thrust and support element comprises an element body of the box type; and wherein 
 said box body comprises a metal sheet cut and shaped and/or bent; and 
 said thrust and support element comprises a support surface adapted to rest the element on an abutment stop adapted to allow the rest and support of the thrust and support element to counteract the action of the traction cable and for resting the ends of the jaws. 
 
     
     
       9. The assembly of  claim 1 , wherein the abutment counter-surface is integral with said thrust and support element. 
     
     
       10. The assembly of  claim 1 , wherein the lever abutment surface and the abutment counter-surface are parallel to a primary direction of the traction cable. 
     
     
       11. The assembly of  claim 1 , wherein the lever abutment surface and the abutment counter-surface are perpendicular to a tangential spring connected to the first and second jaws to recall them away from the inner cylindrical surface of a bell upon the ending of the braking action. 
     
     
       12. A brake comprising an assembly comprising:
 a thrust and support element comprising a first thrust end of thrust and support element adapted to cooperate with a first jaw of a brake; said thrust and support element comprising a second thrust and support element end; 
 a lever rotatably supported to said thrust and support element for rotating at least along a rotation thrust direction; 
 said lever comprising a first lever end adapted to cooperate with a second jaw of the brake; 
 said lever comprising a second lever end, wherein said second lever end comprises a hooking seat; and 
 wherein said hooking seat is adapted to firmly receive a connecting portion of a coupling end of a traction cable, said traction cable having a cable body capable of an elastic flexural deformation that allows it to return to the straight position when the bending stress is removed; 
 said lever being adapted to rotate only when subjected to the traction action of the traction cable, for acting with the first lever end against said second jaw of brake; 
 wherein 
 said thrust and support element comprises an inner element wall which at least partly delimits a guide channel; and 
 said lever comprises a lever inclined wall which at least partly delimits said guide channel; 
 wherein a safety distance (D) between a first straight line (R 1 ), parallel to a rectilinear extension of the traction cable in a non-bent position, passing by a lever end located at an end of the coupling end of the lever, and a second straight line (R 2 ), parallel to the rectilinear extension of the traction cable in a non-bent position, passing by an inner wall end located at the end of an inner element wall which substantially faces the lever 
 wherein said safety distance (D) is less than a maximum transverse dimension (K) of said coupling end
     D<K    
 
 
       and wherein said inner element wall and the lever inclined wall therebetween define a minimum distance (d), wherein said maximum transverse dimension (K) is equal or less than the minimum distance (d) between said inner element wall and said lever inclined wall;
     K≥d    
 wherein 
 said lever comprises a lever abutment surface which cooperates with an abutment counter-surface provided in said thrust and support element to prevent a free rotation of the lever in the opposite direction to said rotation thrust direction; 
 said thrust and support element and said second lever end define said guide channel which allows the passage of at least the coupling end when the cable body is elastically bent, to maintain said lever in a stationary position during both assembly or disassembly of the traction cable; 
 said guide channel allowing the coupling end to rotate about said second lever end and engage with said hooking seat upon the elastic return of the cable body in a cable body position substantially straight, preventing the rotation of the lever in the opposite direction to said rotation thrust direction when the coupling end rotates about said second lever end. 
 
     
     
       13. The brake of  claim 12 , wherein said brake is of the drum-in-hat type in which the jaws cooperate with an inner cylindrical surface of a bell of a disc for disc brake. 
     
     
       14. The brake of  claim 12 , wherein
 a return spring cooperates with said jaws to hold them in axial abutment against said disc-shaped support plate; and 
 said brake comprises a tangential spring connected to said jaws to recall away from said inner cylindrical surface of the bell upon ending of the braking action; and 
 said brake comprises a clearance recovery device adapted to maintain a predetermined distance of the jaws from the inner cylindrical surface of the bell in the event of wear of the jaws. 
 
     
     
       15. The brake of  claim 14 , wherein the lever abutment surface and the abutment counter-surface are perpendicular to the tangential spring connected to the first and second jaws to recall them away from the inner cylindrical surface of the bell upon the ending of the braking action. 
     
     
       16. The brake of  claim 12 , wherein a disc-shaped support plate is comprised, adapted for resting the jaws in an axial direction or a direction parallel to or coincident with the axis of rotation of the disc of disc brake, disc-shaped support plate which closes the compartment formed by the bell. 
     
     
       17. The brake of  claim 12 , wherein the lever abutment surface and the abutment counter-surface are parallel to a primary direction of the traction cable. 
     
     
       18. A brake actuation assembly, comprising:
 a thrust and support element comprising a first thrust end of thrust and support element adapted to cooperate with a first jaw of a brake; said thrust and support element comprising a second thrust and support element end; 
 a lever rotatably supported to said thrust and support element for rotating at least along a rotation thrust direction; 
 said lever comprising a first lever end adapted to cooperate with a second jaw of the brake; 
 said lever comprising a second lever end, wherein said second lever end comprises a hooking seat; and 
 wherein said hooking seat is adapted to firmly receive a connecting portion of a coupling end of a traction cable, said traction cable having a cable body capable of an elastic flexural deformation that allows it to return to the straight position when the bending stress is removed; 
 said lever being adapted to rotate only when subjected to the traction action of the traction cable, for acting with the first lever end against said second jaw of brake; wherein 
 said lever comprises a lever abutment surface which cooperates with an abutment counter-surface provided in said thrust and support element to prevent a free rotation of the lever in the opposite direction to said rotation thrust direction; 
 said thrust and support element and said second lever end define said guide channel which allows the passage of at least the coupling end when the cable body is elastically bent; 
 said guide channel allowing the coupling end to rotate about said second lever end and engage with said hooking seat upon the elastic return of the cable body in a cable body position substantially straight, preventing the rotation of the lever in the opposite direction to said rotation thrust direction when the coupling end rotates about said second lever end, 
 wherein the lever abutment surface and the abutment counter-surface are parallel to a primary direction of the traction cable, and/or wherein the lever abutment surface and the abutment counter-surface are perpendicular to a tangential spring connected to the first and second jaws to recall them away from a inner cylindrical surface of the bell upon the ending of the braking action. 
 
     
     
       19. A brake comprising an assembly comprising:
 a thrust and support element comprising a first thrust end of thrust and support element adapted to cooperate with a first jaw of a brake; said thrust and support element comprising a second thrust and support element end;
 a lever rotatably supported to said thrust and support element for rotating at least along a rotation thrust direction; 
 said lever comprising a first lever end adapted to cooperate with a second jaw of the brake; 
 said lever comprising a second lever end, wherein said second lever end comprises a hooking seat; and 
 wherein said hooking seat is adapted to firmly receive a connecting portion of a coupling end of a traction cable, said traction cable having a cable body capable of an elastic flexural deformation that allows it to return to the straight position when the bending stress is removed; 
 said lever being adapted to rotate only when subjected to the traction action of the traction cable, for acting with the first lever end against said second jaw of brake; 
 
 wherein
 said lever comprises a lever abutment surface which cooperates with an abutment counter-surface provided in said thrust and support element to prevent a free rotation of the lever in the opposite direction to said rotation thrust direction; 
 said thrust and support element and said second lever end define said guide channel which allows the passage of at least the coupling end when the cable body is elastically bent; 
 said guide channel allowing the coupling end to rotate about said second lever end and engage with said hooking seat upon the elastic return of the cable body in a cable body position substantially straight, preventing the rotation of the lever in the opposite direction to said rotation thrust direction when the coupling end rotates about said second lever end, 
 wherein the lever abutment surface and the abutment counter-surface are parallel to a primary direction of the traction cable, and/or wherein the lever abutment surface and the abutment counter-surface are perpendicular to a tangential spring connected to the first and second jaws to recall them away from a inner cylindrical surface of the bell upon the ending of the braking action.